1. Field of the Invention
The invention relates to a coaxial cigarette including a rod comprising a rod core, a rod core wrapping, a rod jacket and a rod jacket wrapping; and a filter comprising a filter core, a filter core wrapping, a filter jacket and a filter jacket wrapping, wherein a cross stream barrier (smoke flow stopper) is provided between said rod core and said filter jacket and/or said rod jacket and said filter core in the zone joins said rod core wrapping and said filter core wrapping.
2. Description of the Related Art
Coaxial cigarettes are designed and produced to enable the smoking and puffing performance to be influenced to a greater extent by the design configuration of the cigarette. One option with coaxial cigarettes is separate treatment of the flows from the rod jacket and the rod core of the coaxial rod through the filter jacket and filter core of the coaxial filter.
In the production of coaxial filter cigarettes, the same as in the production of usual filter cigarettes, the filter is placed up against the rod where it is secured in place by means of a tipping paper placed thereon. This automatically results in coaxial cigarettes having gaps between the end of the rod core wrapping on the filter side and the end of the filter core wrapping on the rod side. Considered microscopically, i.e. when taking into account the flow paths of smoke particles approximately 0.1 mm in size these gaps are to be viewed as being decidedly substantial.
This means that when a separate treatment of the smoke streams from the corresponding rod segments is intended, i.e. when the smoke from the rod jacket is to pass exclusively through the filter core and the smoke from the rod core is to pass exclusively through the filter jacket, then suitable measures need to be taken in accordance with prior art to prevent mis-directed flow through the gaps. As a result of this, coaxial cigarettes known hitherto are subject to heavy restrictions since the flow resistances of the jackets and cores of rod and filter need to be precisely matched. This results in significant restrictions as regards the packing densities achievable in the rod, the usable grade or of other blend components, the coaxial filter employed as well as the achievable condensate target values.